Process for producing nitrogenous 5-membered cyclic compound
AssigneeJapan Science and Technology Agency
InventorsShu Kobayashi, Yasuhiro Yamashita
Life of this patent
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Abstract
A method of the intramolecular and intermolecular cyclization of an N-acylhydrazone for obtaining a pyrazoline skeleton or pyrazolidine skeleton under ordinary conditions with high stereoselectivity and in high yield. An N-acylhydrazone represented by the following formula (I): (wherein R1 and R2 are the same or different and each represents hydrogen or a hydrocarbon group and Ar represents an optionally substituted aromatic hydrocarbon group) is converted to an N-acylpyrazoline derivative with high stereoselectivity in the presence of a Lewis acid catalyst or asymmetric Lewis acid catalyst.
Claims4
A process for a reaction of intramolecular cyclization of an N-acylhydrazone
- wherein an N-acylhydrazone represented by the following formula (I)
- (wherein R1 and R2 are the same or different and each represents a hydrogen atom or a hydrocarbon group, and Ar represents an optionally substituted aromatic hydrocarbon group)
- is subjected to a reaction with a Lewis acid catalyst to obtain an N-acylpyrazoline derivative represented by the following formula (II)
- (wherein R1, R2 and Ar have the same meanings as those indicated above).
A process for a reaction of asymmetric intramolecular cyclization of an N-acylhydrazone wherein an N-acylhydrazone represented by the following formula (I)
- (wherein R1 and R2 are the same or different and each represents a hydrogen atom or a hydrocarbon group, and Ar represents an optionally substituted aromatic hydrocarbon group)
- is subjected to a reaction with an asymmetric Lewis acid catalyst, which can be obtained by mixing a zirconium alkoxide or zirconium dialkoxide dihalide represented by the following formula (III)
- ZrP2Q2 (III)
- (wherein P represents an alkoxy group, and Q represents an alkoxy group or a halogen atom)
- and a binaphthol derivative represented by the following formula (IV)
- (wherein X represents a hydrogen atom, a halogen atom, a hydrocarbon group or a perfluoroalkyl group;
- Y represents a hydrogen atom, a halogen atom, a hydrocarbon group or a perfluoroalkyl group;
- and X and Y may be the same.) to obtain an optically active N-acylpyrazoline derivative represented by the following formula (II′)
- (wherein R1, R2 and Ar have the same meanings as those indicated above).
A process for a reaction of asymmetric intermolecular cyclization of an N-acylhydrazone wherein an N-acylhydrazone represented by the following formula (V)
- (wherein R3 represents an optionally substituted hydrocarbon group and Ar represents an optionally substituted aromatic hydrocarbon group)
- is subjected to a reaction with an olefinic compound represented by the following formula (VI)
- (wherein R4 and R5 are the same or different and each represents a hydrogen atom or a substituent group selected from the group consisting of hydrocarbon group, alkoxy group and alkylthio group and at least one of R4 and R5 is other than a hydrogen atom) in the presence of an asymmetric Lewis acid catalyst, obtained by mixing a zirconium alkoxide or zirconium dialkoxide dihalide represented by the following formula (III)
- ZrP2Q2 (III)
- (wherein P represents an alkoxy group and Q represents an alkoxy group or a halogen atom)
- and a binaphthol derivative represented by the following formula (IV)
- (wherein X represents a hydrogen atom, a halogen atom, a hydrocarbon group or a perfluoroalkyl group, and Y represents a hydrogen atom, a halogen atom, a hydrocarbon group or a perfluoroalkyl group and X and Y may be the same.) to obtain an optically active N-acylpyrazolidine derivative represented by the following formula (VII)
- (wherein R3 to R5 and Ar have the same meanings as those indicated above).
Dependencies are inferred from the claim text.